El CO2, un factor que puede inhibir el efecto bactericida de ciprofloxacina en Escherichia coli

Abstract

Oxidative stress is defined as an imbalancebetween oxidants and antioxidants substances. Several compounds, includingantibiotics, are capable of generating oxidative stress in bacteria. The aim ofthis work was contribute to the understanding of action mechanism ofciprofloxacin (CIP) as generator of oxidative damage in Escherichia coli by assessing oxidative stress in controlledatmospheres of CO2 to evaluate their potential implications forhuman health. We determined the production of reactive oxygen species (ROS) mediatedby CIP under two different conditions of CO2 by spectrofluorometry usingH2-DCFDA as fluorescent probe. It was observed that CO2modifies CIP antibacterial activity against E.coli ATCC 25922. CIP 0.5 µg/mL showed a reduction of 2 log10 inbactericidal effect for the two conditions tested of CO2. At lowerconcentration of CO2 (50 ppm), ROS production increases until 2 h20.1 and 40.8 % with CIP 0.5 and 50 µg/mL; respectively. At higherconcentration of CO2 (5 %), CIP 0.5 µg/mL generates a greaterincrease in ROS (26.2%) than 50 µg/mL (14.6%). This behavior observed indifferent conditions of CO2 indicates that the activity of CIP mediatedby ROS generation is modified not only by the presence of CO2 butalso by its concentration.